Fill it with ice and water, then drain.

Ice and water. Fill the cooler about halfway with ice, add cold water, close it, and let it sit for 10–15 minutes. Dump everything out before you put your actual food and drinks in.

The water transfers cold way faster than air ever could. Just ice alone leaves gaps and takes forever. Ice water coats every surface in seconds. The result is a cooler that’s already cold inside, so your fresh ice lasts longer and your drinks stay colder.

A bag of ice is a couple bucks. Do this every time you head out.